Sophrosyne cantractia, Lowry & Stoddart, 2010

Lowry, J. K. & Stoddart, H. E., 2010, Sophrosynidae, a new family in the Lysianassoidea (Crustacea: Amphipoda) with a revision of the genus Sophrosyne, Zootaxa 2370 (1), pp. 1-35 : 10-13

Sophrosyne cantractia sp. nov.

(Figs 4, 5)

Type material. HOLOTYPE, female, ovigerous (2 eggs), 5.8 mm, MV J38218 , western part of MacRobertson Shelf , Antarctica (66°55.51'S 62°32.72'E to 66°55.33'S 62°32.16'E), 113 m, epibenthic sled, M. O'Loughlin on RSV Aurora Australis , 11 February 1993 (stn AA93-124) . PARATYPES: 1 specimen, 4.2 mm, MV J38219 , western part of MacRobertson Shelf , Antarctica (66°53.69'S 63°06.34'E to 66°53.67'S 63°05.51'E), 367–439 m, epibenthic sled, M. O'Loughlin on RSV Aurora Australis , 11 February 1993 (stn AA93-125) ; 2 juveniles, MV J60736 and MV J60737 , off Enderby Land , Antarctica, Southern Ocean (65°56.40'S 50°52.10'E), 386–400 m, shelly mud, silt and bryozoan shell, epibenthic sled, M. Norman on MS Nella Dan, 15 November 1985 (stn HRD 010) .

Type locality. Western part of MacRobertson Shelf, Antarctica (66°55.51'S 62°32.72'E to 66°55.33'S 62°32.16'E), 113 m.

Etymology. The specific name is contrived as an anagram of the specific name of the neighbouring species, Sophrosyne antarctica .

Diagnostic description. Head lateral cephalic lobe small, narrowly rounded; eyes apparently absent. Antenna 1 peduncular article 1 short, length 1.3 x breadth; accessory flagellum medium length, 0.5 x primary flagellum, article 1 short, 1.3 x article 2; flagellum 7-articulate, without callynophore. Antenna 2 peduncular article 3 0.6 x article 4; flagellum 7-articulate. Mandible incisors with straight margins; palp article 2 slender, 1 x article 3, with 2 submarginal posterodistal A2-setae, D2-setae present, article 3 length 7 x breadth, without D3-setae, with 3 apical E3-setae. Maxilla 1 outer plate with setal-teeth in a 2/3 arrangement. Maxilla 2 inner plate narrow, outer plate broader; inner plate length 0.66 x outer plate. Maxilliped inner plate subrectangular, with 1 apical, nodular robust setae; outer plate submarginal setae long, simple; palp article 2 broad, length 1.8 x breadth, 1.1 x article 3, article 3 slender, length 2.6 x breadth, dactylus with unguis vestigial. Gnathopod 1 basis length 1.8 x breadth, anterior margin with slender setae; ischium length 1.1 x breadth; merus, posterior margin lined with long slender setae; carpus length 0.5 x propodus; propodus length 1.8 x breadth, posterior margin slightly concave, with robust setae and simple, slender setae, palm margin straight, posterodistal corner with produced subacute spine bearing vestigial seta. Gnathopod 2 minutely subchelate; ischium length 3 x breadth; carpus long, length 3.8 x breadth, posterior margin straight; propodus subrectangular, long, length 2.3 x breadth; palm transverse, with convex, serrate margin. Pereopod 3 merus not expanded anteriorly. Pereopod 4 merus weakly expanded anteriorly. Pereopod 5 basis moderately expanded posteriorly; merus moderately expanded posteriorly. Pereopod 6 coxa small, slightly lobate posteriorly; merus expanded posteriorly. Pereopod 7 basis posterior margin slightly rounded, minutely crenate, posteroventral margin straight, posteroventral lobe not extending beyond ischium; merus slightly expanded posteriorly; propodus with setae along anterior margin. Epimeron 3 posterior margin with strong upturned spine above rounded posteroventral corner. Urosomite 1 with anterodorsal notch and rounded boss, without lateral flange. Uropod 1 rami subequal in length; outer ramus with 2 dorsal robust setae; inner ramus with 1 dorsal robust seta. Uropod 2 rami subequal in length; outer ramus with robust setae. Uropod 3 peduncle length 1.4 x breadth; rami subequal in length. Telson longer than broad, length 1.3 x breadth, moderately cleft (53%), distal margins rounded, with 1 apical slender seta on each lobe.

Remarks. See remarks under S. californica .

Distribution. Off MacRobertson Shelf and Enderby Land, east Antarctica, in 113–439 m depth.